As known, a scroll compressor may include:                a closed container,        a compression unit configured to compress refrigerant and including a fixed scroll and an orbiting scroll,        a drive shaft configured to drive the orbiting scroll in an orbital movement, the drive shaft including notably:                    a lubrication channel configured to be supplied with oil from an oil sump by an oil pump driven by the drive shaft, the lubrication channel extending over at least a part of a length of the drive shaft, and            lubrication holes fluidly connected to the lubrication channel and emerging in an outer wall of the drive shaft, the lubrication holes being axially offset along the rotation axis of the drive shaft,                        a driving unit coupled to the drive shaft and arranged for driving in rotation the drive shaft about a rotation axis, and        bearings axially offset along the rotation axis of the drive shaft and each configured to engage the drive shaft.        
During rotation of the drive shaft, the lubrication channel is supplied with oil by the oil pump, and the supplied oil is then fed, through centrifugal force and via the lubrication holes, to bearing surfaces of the bearings, which leads to a lubrication of the latter.
In order to ensure a satisfactory lubrication of the bearings, the drive shaft is preferably provided with one lubrication hole in front of each bearing, and each lubrication hole preferably emerges in an inner wall portion of the lubrication channel opposite to the rotation axis of the drive shaft such that the oil supplied in the lubrication channel flows by centrigugation along said inner wall portion and easily enters the lubrication holes through centrifugal force.
However, the final angular location of the lubrication holes depends on the angular location of the radial loads applied between the drive shaft and the bearings during rotation of the drive shaft. Indeed, if the lubrication holes are located at the same angular location than that of the radial loads applied between the drive shaft and the bearings, then the pressure created by said radial loads at each lubrication hole will prevent exit of oil from the corresponding lubrication hole, which will impede a satisfactory lubrication of the bearings.
Therefore, the appropriate angular location of the lubrication holes with respect to said inner wall portion of the lubrication channel cannot always be respected, which leads to a decrease of the bearings lubrication quality.
Further, as the angular location of the radial loads applied between the drive shaft and the bearings depends on the drive shaft speed, in addition to the operating conditions, the use of a variable-speed motor as driving unit may render difficult the selection of the most appropriate angular location for the lubrication holes.